NAME

       r.out.mpeg  - Converts raster map series to MPEG movie.

KEYWORDS

       raster, export, output, animation

SYNOPSIS

       r.out.mpeg
       r.out.mpeg --help
       r.out.mpeg      [-c]     view1=name[,name,...]      [view2=name[,name,...]]       [view3=name[,name,...]]
       [view4=name[,name,...]]  output=name  [quality=integer]   [--overwrite]  [--help]  [--verbose]  [--quiet]
       [--ui]

   Flags:
       -c
           Convert on the fly, uses less disk space
           Requires r.out.ppm with stdout option

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       view1=name[,name,...] [required]
           Name of input raster map(s) for view no.1

       view2=name[,name,...]
           Name of input raster map(s) for view no.2

       view3=name[,name,...]
           Name of input raster map(s) for view no.3

       view4=name[,name,...]
           Name of input raster map(s) for view no.4

       output=name [required]
           Name for output file

       quality=integer
           Quality factor (1 = highest quality, lowest compression)
           Options: 1-5
           Default: 3

DESCRIPTION

       r.out.mpeg  is  a  tool for combining a series of GRASS raster maps into a single MPEG-1 (Motion Pictures
       Experts Group) format file.  MPEG-1 is a "lossy"  video  compression  format,  so  the  quality  of  each
       resulting  frame  of the animation will be much diminished from the original raster image.  The resulting
       output file may then be viewed using your  favorite  mpeg-format  viewing  program.   MPEG-2  and  MPEG-4
       provide much better quality animations.

       The user may define up to four "views", or sub-windows, to animate simultaneously.  e.g., View 1 could be
       rainfall, View 2 flooded areas, View 3 damage to bridges or levees, View 4  other  economic  damage,  all
       animated  as a time series. A black border 2 pixels wide is drawn around each view. There is an arbitrary
       limit of 400 files per view (400 animation frames).   Temporary  files  are  created  in  the  conversion
       process, so lack of adequate tmp space could also limit the number of frames you are able to convert.

       The  environment  variable  GMPEG_SIZE  is checked for a value to use as the dimension, in pixels, of the
       longest dimension of the animation image.  If GMPEG_SIZE is not set, the animation size defaults  to  the
       rows  &  columns  in  the current GRASS region, scaling if necessary to a default minimum size of 200 and
       maximum of 500.  These size defaults are overridden when using the -c flag (see below). The resolution of
       the  current GRASS region is maintained, independent of image size.  Playback programs have to decode the
       compressed data "on-the-fly", therefore smaller dimensioned animations will provide  higher  frame  rates
       and smoother animations.

       UNIX - style wild cards may be used with the command line version in place of a raster map name, but wild
       cards must be quoted.

       A quality value of quality=1 will yield higher quality images, but with  less  compression  (larger  MPEG
       file  size). Compression ratios will vary depending on the number of frames in the animation, but an MPEG
       produced using quality=5 will usually be about 60% the size of the MPEG produced using quality=1.

Example

       r.out.mpeg view1="rain[1-9]","rain1[0-2]" view2="temp*"

       If the number of files differs for each view, the view with the fewest files will determine the number of
       frames in the animation.

       With -c flag the module converts "on the fly", uses less disk space by using r.out.ppm with stdout option
       to convert frames as needed instead of converting all frames to  ppm  before  encoding.   Only  use  when
       encoding a single view.  Use of this option also overrides any size defaults, using the CURRENTLY DEFINED
       GRASS REGION for the output size. So be careful to set region to a reasonable size prior to encoding.

KNOWN ISSUES

       MPEG images must be 16-pixel aligned for successful  compression,  so  if  the  rows  &  columns  of  the
       calculated  image  size  (scaled,  with borders added) are not evenly divisible by 16, a few rows/columns
       will be cut off the bottom & right sides of the image. The MPEG format is optimized  to  recognize  image
       MOTION, so abrupt changes from one frame to another will cause a "noisy" encoding.

NOTES

       This program requires the program mpeg_encode (aka ppmtompeg):

       MPEG-1 Video Software Encoder
       (Version 1.3; March 14, 1994)

       Lawrence  A.  Rowe,  Kevin  Gong,  Ketan  Patel, and Dan Wallach Computer Science Division-EECS, Univ. of
       Calif. at Berkeley

       Available from Berkeley: http://biowiki.org/BerkeleyMpegEncoder
       or as part of the netpbm package (ppmtompeg): http://netpbm.sourceforge.net

       Use of the -c flag requires the r.out.ppm GRASS module with the stdout option.

SEE ALSO

       r.out.ppm

AUTHOR

       Bill Brown, U.S. Army Construction Engineering Research Laboratories

SOURCE CODE

       Available at: r.out.mpeg source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual